Boxwoods are great hedge plants, long cherished by gardeners for their dense foliage and adaptability to shearing into various forms. One of the most common pests of the shrub areleafminers, which tunnel between the upper and lower leaf surfaces where they are hard to control with insecticidal sprays. The unsightly symptom is yellow, puckered areas in the leaves and early leaf drop. Gardeners who love their boxwoods but don't love spraying will be happy to hear that researchers at the University of Maryland have been studying 7 boxwood cultivars for resistance to the leafminer. Two Buxus sempervirens cultivars, 'Handsworthiensis' and 'Varder Valley', have demonstrated "extraordinarily high levels of resistance" to leafminers.